21688604105 has 8 divisors (see below), whose sum is σ = 29744371392. Its totient is φ = 14872185648.

The previous prime is 21688604023. The next prime is 21688604137. The reversal of 21688604105 is 50140688612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21688604105 - 2¹² = 21688600009 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309837167 + ... + 309837236.

It is an arithmetic number, because the mean of its divisors is an integer number (3718046424).

Almost surely, 2^21688604105 is an apocalyptic number.

It is an amenable number.

21688604105 is a deficient number, since it is larger than the sum of its proper divisors (8055767287).

21688604105 is an equidigital number, since it uses as much as digits as its factorization.

21688604105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619674415.

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 21688604105 in words is "twenty-one billion, six hundred eighty-eight million, six hundred four thousand, one hundred five".